Electro-thermal chemical igniter and connector

ABSTRACT

An ETC igniter and compatible electrical connector for enabling an ETC gun to be used in a battlefield setting in close proximity with personnel and sensitive electronic equipment. This is accomplished by providing a current path to and from the igniter that is electrically isolated from all other portions of the gun. The connector and igniter are adapted to be capable of withstanding the high connection forces necessary to prevent arcing and the extreme stresses imposed during firing of the gun.

FIELD OF THE INVENTION

This invention relates to electro-thermal chemical guns, and moreparticularly, to high-energy igniters and power connectors forelectro-thermal chemical cartridges.

BACKGROUND OF THE INVENTION

Electro-thermal chemical (ETC) gun systems have been developed inresponse to a need for improved medium and large caliber gunperformance. Typically, an ETC ammunition round has an igniter assembly.The igniter assembly serves to generate a high-energy plasma fromelectrical energy supplied to the igniter, and to inject the plasma intoa mass of chemical propellant, which is then ignited by thehigh-temperature plasma. The very high energy and temperature of theplasma enables the use of multi-layer and higher density chemicalpropellants. Such propellants, although harder to ignite, enable astronger and more lengthy useful pressure pulse to the projectile,thereby improving gun system performance. One example of such apropellant system is disclosed in U.S. Pat. No. 6,167,810, which isassigned to the owner of the present invention, and which is herebyfully incorporated herein by reference. In addition, the plasma energyitself may serve to provide an additional accelerating force to theprojectile, thereby improving gun performance.

Examples of plasma igniter apparatus for ETC gun systems are disclosedin U.S. Pat. Nos. 5,231,242, 5,287,791, 5,503,081, 5,767,439, 5,444,208,5,830,377, all assigned to the owner of the present invention, and eachof which is hereby fully incorporated by reference herein. In addition,further examples of an ETC plasma igniter are disclosed in co-pendingU.S. patent application Ser. No. 09/767,542, assigned to the owner ofthe present invention, and fully incorporated herein by reference.

Generally, it is desirable that an ETC igniter apparatus supply about100 kJ or more of plasma energy to the mass of chemical propellant in anETC cartridge. As a consequence, it is necessary to supply a slightlygreater amount of electrical energy to the igniter. Moreover, foreffective plasma formation, the electrical energy must be supplied overa time period measured in milliseconds. As a result, very highelectrical currents at very high voltages are necessary to transfer theenergy in the requisite amount of time. Currents over 50 kA or more areoften necessary.

Transmission of electrical power at very high current levels presentsunique challenges in the design of conductors and connection equipment.Excessive resistance in the current path will cause very rapid anddestructive heating effects. In addition, strong magnetic fields may becreated which can cause catastrophic failure of conductors andconnectors. Moreover, connection interfaces between components in theconductive path may be prone to arcing if contaminated or ifinsufficient force holds the components together. As a result, it isnecessary to provide a strong biasing force to press together componentsin the current path. This biasing force may reach levels over 1000pounds of force, imposing high stress loads on components.

Transmission of electrical power at high currents to a plasma igniter inan ETC gun application presents even greater challenges due to theextreme physical loading characteristics of the application. The breechassembly of a typical 120 mm ETC gun may be subjected to a load of morethan 2,000,000 pounds upon firing, resulting in instantaneous stressloads of more than 100,000 p.s.i. in certain components. In addition,the gun and breech assembly must be designed to permit recoil. Thus,power cables must be sufficiently flexible to enable recoil, which mayexceed two feet in some cases.

Specialized coaxial cables and connectors have been developed inresponse to the above challenges. For example, a high energy flexiblecoaxial cable and connector suitable for use in ETC gun applications aredisclosed in U.S. Pat. No. 5,656,796, assigned to the owner of thepresent invention, and fully incorporated herein by reference. Inaddition, embodiments of another high energy power connector usable inETC gun applications are disclosed in U.S. Pat. No. 5,220,126, assignedto the owner of the present invention, also fully incorporated herein byreference.

Past solutions, although generally successful in conveying power to anETC gun plasma igniter while overcoming some of the electrical andphysical problems described above, have not been fully suitable forpractical use in a battlefield setting for a variety of reasons. Thecurrent return path in prior solutions typically leads through portionsof the gun that may be exposed to human contact. Due to the highvoltages and current present in the return path, such exposed portionscan present an extreme life safety hazard to personnel operating thegun, particularly where the gun may be located in a confined space suchas a tank turret. Moreover, sensitive electronic devices, which may beused for communication, fire control, or other purposes, are subject todamage from stray currents or strong magnetic fields generated by thecurrent.

In addition, the power connection in some prior art devices relies onpermanent deformation of the connection components or on cumbersome andcomplicated connectors in order to achieve sufficient connection forceto avoid arcing. These methods and devices are generally unsuitable fora battlefield device which must be capable of repeated, reliable, andrapid connection and disconnection so that a relatively high rate offire may be achieved.

What is still needed is a high-energy power connection apparatus,especially adapted for use in a battlefield setting, that is suitablefor connecting an ETC igniter apparatus in an ETC gun with a high-energypower source.

SUMMARY OF THE INVENTION

The ETC igniter and compatible electrical connector hereof, enable anETC gun to be used in a battlefield setting in close proximity withpersonnel and sensitive electronic equipment. This is accomplished byproviding a current path to and from the igniter that is electricallyisolated from all other portions of the gun. The connector and igniterare adapted to be capable of withstanding the high connection forcesnecessary to prevent arcing and the extreme stresses imposed duringfiring of the gun.

A combination high-energy electrical connector and electro-thermalchemical igniter includes an igniter having a base portion adapted to beoperably coupled with an ammunition cartridge case. An electricalconnector located in the igniter base portion includes a supplyconductor, a return conductor, and a plurality of insulators arranged soas to electrically isolate the supply and return conductors from thebase portion. The connector includes a body portion adapted to beoperably coupled with a gun breech, a supply conductor having a distalportion adapted to engage and electrically connect with the supplyconductor of the igniter, and a return conductor having a distal portionadapted to engage and electrically connect with the return conductor ofthe igniter. Insulators are arranged so as to electrically isolate thesupply and return conductors from the body portion. The connector andelectrical connector portion of the igniter may be coaxial. In such acoaxial arrangement, the electrical connector portion of the igniter mayhave a center supply conductor and an annular outer return conductorsurrounding the center supply conductor. The connector may have a centersupply conductor having a distal portion adapted to engage andelectrically connect with the center supply conductor of the igniter,and an annular outer return conductor surrounding the center supplyconductor. The connector further includes a distal portion adapted toengage and electrically connect with the outer supply conductor of theigniter. The supply conductor of the connector may be longitudinallyslidable, with a pre-load spring arranged so as to resist proximalsliding of the supply conductor when the igniter is connected with theconnector.

An electro-thermal chemical gun system according to the invention mayinclude an ammunition round having an electro-thermal chemical igniter,a gun adapted to receive and fire the ammunition round, a high-energypower source, a cable connected to the high-energy power source, and aconnector for connecting the cable to the igniter. The igniter,connector, and cable are adapted to provide a current supply path and acurrent return path, each electrically isolated from the gun.

A method of connecting a power cable from a high energy power sourcewith an igniter in an electro-thermal chemical gun is also disclosed.The method may include the steps of:

(a) providing the igniter with an electrical connector portion includinga pair of conductors, one of the conductors connected with an anode ofthe igniter, the other conductor connected with a cathode of theigniter, each of the conductors being insulated so as to be electricallyisolated from all other portions of the igniter;

(b) forming an electrical connector having a pair of conductors and abody portion, the body portion operably coupleable to the gun, each ofthe pair of conductors adapted to engage and connect with a separate oneof the pair of conductors of the igniter when the electrical connectoris engaged with the igniter, each of the pair of conductors beinginsulated so as to be electrically isolated from all other portions ofthe electrical connector and the gun;

(c) connecting each of the pair of conductors of the electricalconnector with a separate conductor of the power cable;

(d) connecting the electrical connector with the electrical connectorportion of the igniter; and

(e) forcing the electrical connector and the igniter together with afirst biasing force of sufficient magnitude to prevent arcing betweenthe conductors of the igniter and the conductors of the electricalconnector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of an ETC gun system;

FIG. 2 is a cross-sectional view of an electrical connector and ETCigniter in a cartridge case;

FIG. 2A is an end view of the igniter depicted in FIG. 2; and

FIG. 3 is a cross-sectional view of an alternative embodiment of anigniter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An electro-thermal chemical gun system 4 is depicted in FIG. 1. Gunsystem 4 generally includes gun 5 and high-energy power source 6. Gun 5generally includes barrel 7 with breech portion 8, chassis portion 9,and power cable 10. Chassis portion 9 may have wheels 11 for mobility.

A power connector and electro-thermal chemical (ETC) igniter assembly 10a according to the present invention is depicted in FIG. 2. The assembly10 a generally includes coaxial power cable 10, power connector 12, andbasepad igniter 14.

Coaxial cable 10 generally includes a center conductor 16, and an outerconductor 18, separated by insulation layer 20, and covered byinsulation jacket 22. One example of a suitable coaxial cable assemblyis also disclosed in U.S. Pat. No. 5,656,796, previously incorporatedherein by reference.

Power connector 12, generally includes center conductor assembly 24,outer conductor assembly 26, and outer sleeve 28. Connector 12 isgenerally cylindrical and presents a longitudinal axis, annotated A-A inthe drawings.

Center conductor assembly 24 of power connector 12 generally includescenter pin 30, insulating sleeves 32, 34, and preload spring 36.Proximal end 38 of center pin 30 has an enlarged portion 40 with asocket 42 for receiving the distal end 44 of center conductor 16 ofcoaxial cable 10. Distal end 46 of center pin 30 may be conicallyshaped, as depicted in the drawings, for improved electricalconductivity. Insulating sleeve 32, which may be formed from a materialhaving a high compressive strength such as ceramic, is slidably disposedaround insulation layer 20. Preload spring 36 bears on the proximal end48 of insulating sleeve 32 and supplies a biasing force which pressesinsulating sleeve 32 against the proximal end 38 of center pin 30,thereby biasing center pin 30 distally. Pre-load spring 36 is depictedas a Belleville washer, but may also be any other suitable resilientmember. Insulating sleeve 34 is slidably disposed over center pin 30 soas to enable slight longitudinal movement of center pin 30. Insulatingsleeve 30 may be made from any suitable relatively high strengthmaterial such as polycarbonate plastic.

Outer conductor assembly 26 of power connector 12 generally includesconductor portion 50, annular sleeve 52, insulator 54, and insulatingsleeves 56, 58. Conductor portion 50 is generally tubular and may havean interior threaded portion 60 engaged with corresponding threads 62 ofannular sleeve 52. Annular sleeve 52 has a frusto-conical wedge portion64, which projects distally through insulator 54. Insulating sleeve 56,which again may be formed from a high compressive strength material suchas ceramic, is disposed around insulation jacket 22 and islongitudinally sandwiched between shoulder portion 66 of conductorportion 50 and outer sleeve 28. Insulating sleeve 58 electricallyseparates shoulder portion 66 from outer sleeve 28.

Outer sleeve 28, which may be formed from high strength material such ashigh-carbon nickel-chromium-molybdenum alloy steel, may have an exteriorthreaded portion 68 so that connector 10 may be threaded into a bore 70formed in a gun breech 72. Flats 74 may be provided at the proximal end76 of outer sleeve 28 to facilitate manual threading of the connector.Alternatively, connector 10 may be forced into bore 70 by a hydraulic orother machine capable of supplying a force, as will be further explainedhereinbelow.

Basepad igniter 14 generally includes base 78, power connector portion80, plasma containment portion 82, and vent cover 84. Base 78 has athreaded portion 86 so that the igniter 14 may be threaded into acartridge case 88 of an ammunition round from the inside.

Power connector portion 80 generally includes anode 90, cathode 92, wire93, and insulating sleeves 94, 96, 98, 100. Anode 90 has a conicalsocket 102 for receiving the conical shaped distal end 46 of center pin30. Anode 90 is electrically connected with cathode 92 by wire 93, butis otherwise electrically isolated from cathode 92 by cooperatinginsulating sleeves 94, 96. Insulating sleeve 94 may be made from a highcompressive strength insulating material such as ceramic, whileinsulating sleeve 96 may be made from any suitable relativelyhigh-strength material such as polycarbonate plastic.

Cathode 92 has a frusto-conical socket portion 104 for receiving wedgeportion 64 of power connector 12. Cathode 92 is electrically isolatedfrom base 78 by insulating sleeves 98, 100. Again, insulating sleeve 98may be made from ceramic or other similar material having a highcompressive strength.

Plasma containment portion 82 fits over base 78 and has a generallyspiral shaped plasma channel 106 connecting anode 90 and cathode 92.Plasma containment portion 82 is formed from a generally insulativematerial such as plastic. Vent cover 84 is disposed over plasmacontainment portion 82, and has vent apertures 105 leading from plasmachannel 106 to the interior of the cartridge case, which containschemical propellant 108.

The operation of the invention may now be understood with reference toFIG. 1. Outer sleeve 28 is threaded into bore 70 of gun breech 72,causing the conical shaped distal end 46 of center pin 30 to engage andwedge into conical socket 102 of anode 90. As outer sleeve 28 isthreaded further, outer conductor assembly 26 continues to advance withit, wedging frusto-conical wedge portion 64 into socket portion 104 ofcathode 92. Center pin 30, being already in contact with conical socket102, is stationary, but is wedged with steadily increasing pressure intoconical socket 102 through the compression of pre-load spring 36. Outersleeve 28 is advanced until a desired contact force is reached at boththe connections between center pin 30 and socket 102 and between wedgeportion 64 and socket portion 104. These compressive forces in thecurrent path inhibit arcing, which can result in rapid heating anddestruction of the components. The compressive force may preferably bein the range of 800 to 1400 pounds. The high compressive strengthinsulators 32, 56, 94 and 98 transmit the compressive force between themetallic components while also providing the desired electricalisolation.

Once power connector 12 is fully engaged with basepad igniter 14 asdescribed above, a power pulse may be applied to center conductor 16 ofcoaxial cable 10. The power is conducted through center pin 30 to anode90. Wire 93 vaporizes, forming a plasma arc in plasma channel 106 ascurrent flows to cathode 92, and plasma is vented into the chemicalpropellant 108 through vent apertures 105. The current returns throughcathode 92, outer conductor assembly 28 and outer conductor 18.

The current return path is electrically isolated from the cartridge case88 and gun breech 72 by insulators including plasma containment portion82, insulating sleeves 98 and 100, insulator 54, insulating sleeves 56and 58, and insulation jacket 22. Thus, personnel and sensitiveelectronic devices may be located proximate the gun during firingwithout deleterious effects from high voltage and current.

The high strength outer sleeve 28 serves as a containment structure forpower connector 12, preventing destruction of the connector from thestrong magnetic forces caused by the proximity of the supply and returncurrent paths. The high compressive strength insulators used at criticallocations in the connector and igniter serve to transmit the necessarycompressive forces to prevent arcing while also resisting the extremerecoil forces resulting from firing the gun.

An alternative embodiment of an ETC igniter, known as a low-volumeinjector (LVI) igniter is depicted in FIG. 3. Igniter 110 generallyincludes base portion 112, electrical connector portion 114, and plasmarod 116. The igniter 110 presents a longitudinal axis annotated B-B inthe drawings, which is generally coincident with the longitudinal axisof a cartridge case (not depicted).

Base portion 112 has a threaded portion 118 for threading into thecartridge case of an ammunition round from the inside. Base portion 112also includes retainer ring 120 and insulating outer cone 122 forretaining electrical connector portion 114.

Electrical connector portion 114 generally includes center conductor124, anode 126, cathode 128, and outer conductor 130. Wire 131 connectsanode 126 and cathode 128. High compressive strength insulating sleeves132, 134, as well as insulating sleeve 136, serve to isolate centerconductor 124 from cathode 128 and outer conductor 130. Outer cone 122,high compressive strength insulating sleeves 138, 140, and insulatingsleeves 142, 144, electrically isolate cathode 128 and outer conductor130 from base portion 112 and portions of the gun connected with it.Again, center conductor 124 has a conical socket 146 for receiving theconical distal end 46 of electrical connector 12, while outer conductor130 has a socket portion 148 for receiving wedge portion 64.

Plasma rod 116 generally includes tubular portion 150 enclosing a plasmageneration region 151 in the form of plasma channel 152. Wire 131 iscontained in plasma channel 152. Insulator 153 insulates wire 131 fromcenter conductor 124. Vent apertures 154 are provided to vent plasmainto a chemical propellant mixture as before. End cap 156 is disposedover the end of plasma rod 116 and is secured with fastener 158.

In operation, the electrical connector 12 may be engaged with igniter110 in the same manner as previously described. Once engaged, a highenergy current pulse may be supplied through center pin 30 to centerconductor 124 and anode 126. Wire 131 vaporizes, forming a plasma arc inplasma channel 152 as current flows to the cathode 128, and plasma isvented into chemical propellant through vent apertures 154, igniting thepropellant. Current returns through cathode 128, and outer conductor 130to outer conductor assembly 26 of electrical connector 12 and outerconductor 18 of coaxial cable 10.

In the embodiment of FIG. 3, the return current is isolated from baseportion 112 and all portions of the gun connected with it by outer cone122, high compressive strength insulating sleeves 138, 140, andinsulating sleeves 142, 144. Thus, a gun wherein the LVI ETC igniter isemployed may be fired in proximity with personnel and sensitiveelectronic devices without negative effect. Moreover, the highcompressive strength insulating sleeves 132, 134, 138, and 140, serve toeffectively transmit the necessary compressive forces between metalliccomponents necessary to prevent arcing, while also withstanding theextreme loads imposed during gun discharge.

Referring again to FIG. 2, for most uniform ignition of a chemicalpropellant charge 108, it is generally preferred that the plasma arc beexposed to the chemical propellant 108 over a relatively large area. Inthe depicted basepad igniter 14, this is achieved by forming a generallyspiral plasma channel 106 with vent apertures 105 distributed along thelength of channel 106. The spiral configuration and relative length ofthe channel 106 provide a plasma ignition source that is distributedover a relatively large area at the end of a cartridge case 88. Plasmaitself is conductive, however, and as the plasma escapes into thechemical propellant 108 from the vent apertures 105 closest to anode 90in the incipient stages of plasma formation, a lower resistance currentpath may be formed directly from anode 90 to cathode 92 through plasmain the chemical propellant 108. If the bulk of the currentshort-circuits through such a direct path, the result is a moreconcentrated plasma arc with a relatively less uniform ignition of thechemical propellant.

In another embodiment of basepad igniter 14, depicted in plan view inFIG. 2A, the above described short-circuiting is advantageouslyminimized. As depicted, vent cover 84 has been removed, exposing plasmacontainment portion 82. A first primary electrode 160 is connected withanode 90 and a second primary electrode 92 is connected with cathode 92.The primary electrodes 160, 162, are spaced apart a distance annotatedX₁. Wire 93, which is disposed in plasma channel 106, electricallyconnects primary electrodes 160 and 162. In this embodiment, a pluralityof secondary electrodes 164 are located along the length of wire 93.Each secondary electrode 164 is spaced apart a distance, annotated X₂,from each immediately adjacent primary electrode 160, 162, andimmediately adjacent secondary electrode 164. The plasma channel 106 isconfigured, and the secondary electrodes 164 are positioned, so thatdistance X₁ is at least slightly greater than distance X₂. The distancesX₂ between adjacent electrodes 164 along wire 93 need not be equal, solong as each is at least slightly less than distance X₁. In operation,when a current pulse is supplied to anode 90, and the connected primaryelectrode 160, the shorter path and resultantly lower resistance betweenprimary electrode 160 and adjacent secondary electrode 164 causes thebulk of current to flow between those two electrodes, rather thandirectly to cathode 92 through any plasma that may be present inchemical propellant 108. In similar fashion thereafter, the relativelycloser spacing of each adjacent secondary electrode 164 causes thecurrent to flow to it, rather than directly through plasma in thechemical propellant 108. The plasma arc is thereby propagated along theentire length of plasma channel 106 as preferred.

1. A combination high-energy electrical connector and electro-thermalchemical igniter assembly comprising: an electro-thermal chemicaligniter including a base portion adapted to be operably coupled with anammunition cartridge case, and an electrical connector portion in thebase portion, the electrical connector portion including an ignitersupply conductor, an igniter return conductor, and an igniter insulatorportion arranged so as to electrically isolate the igniter supply andigniter return conductors from the base portion, the igniter supplyconductor having a supply socket and the igniter return conductor havinga return socket; and a connector for connecting a power cable to theigniter, the connector including a body portion adapted to be operablycoupled with a gun breech, a connector supply conductor having a distalportion adapted to receivably engage and electrically connect with thesupply socket of the igniter supply conductor to define a current supplypath, a connector return conductor having a distal portion adapted toreceivably engage and electrically connect with the return socket of theigniter return conductor to define a current return path, and aprojecting connector insulator portion arranged so as to electricallyisolate the current supply path and current return path from the bodyportion.
 2. The assembly of claim 1, wherein the electrical connectorportion of the igniter comprises a center igniter supply conductor andan annular outer igniter return conductor surrounding the center ignitersupply conductor and the connector comprises a center connector supplyconductor having a conical-shaped distal portion adapted to engage andelectrically connect with the supply socket of the center igniter supplyconductor, and an annular outer connector return conductor surroundingthe center connector supply conductor and having a wedge-shaped distalportion adapted to engage and electrically connect with the returnsocket of the outer igniter return conductor.
 3. The assembly of claim1, wherein the connector supply conductor is longitudinally slidable,and wherein the connector further includes a pre-load spring arranged soas to resist proximal sliding of the connector supply conductor when theigniter is connected with the connector.
 4. The assembly of claim 1,wherein the igniter is a basepad igniter.
 5. The assembly of claim 1,wherein the igniter is an LVI igniter.
 6. The assembly of claim 1,wherein the connector and the igniter are adapted to be biased togetherwith a force sufficient to prevent arcing between the conductors of theconnector and the conductors of the igniter.
 7. The assembly of claim 1,wherein the igniter insulator portion of said igniter comprises aplurality of insulators.
 8. The assembly of claim 1, wherein theprojecting connector insulator portion of said connector comprises aplurality of insulators.
 9. An electro-thermal chemical gun systemcomprising: a gun having a barrel with a breech, and a breechblock forclosing said breech; an elongate ammunition cartridge including a casewith a closed end, the ammunition cartridge adapted to fit in saidbreech with the closed end in contact with said breechblock; anelectro-thermal chemical igniter in said closed end of said case, saidigniter having an electrical connector portion including a centerconductor and an annular outer conductor surrounding the centerconductor, the igniter further having an insulator portion arranged soas to electrically isolate the outer conductor and the center conductorfrom the case; a coaxial connector operably coupleable with said breechblock, said connector including a center conductor having a distalportion adapted to engage and electrically connect with the centerconductor of the igniter, an annular outer conductor surrounding thecenter conductor and having a distal portion adapted to engage andelectrically connect with the outer conductor of the igniter, and aninsulator portion arranged so as to electrically isolate the outerconductor and the center conductor from the body portion, wherein saidcoaxial connector and said electrical connector portion of said igniterare adapted to carry a high-energy electrical current to and from saidigniter with said gun being electrically isolated from said high-energyelectrical current.
 10. The system of claim 9, wherein the centerconductor of the coaxial connector is longitudinally slidable, andwherein the coaxial connector further includes a preload spring arrangedso as to resist proximal sliding of the center conductor when theigniter is connected with the coaxial connector.
 11. The system of claim9, wherein the igniter is a basepad igniter.
 12. The system of claim 9,wherein the igniter is an LVI igniter.
 13. The system of claim 9,wherein the coaxial connector and the igniter are adapted to be biasedtogether with a force sufficient to prevent arcing between theconductors of the coaxial connector and the conductors of the igniter.14. The system of claim 9, wherein the insulator portion of said ignitercomprises a plurality of insulators.
 15. The system of claim 9, whereinthe insulator portion of said connector comprises a plurality ofinsulators.
 16. A method of connecting a power cable from a high energypower source with an igniter in an electro-thermal chemical gun, themethod comprising the steps of: providing the igniter with an electricalconnector portion, said connector portion including a pair ofconductors, one of said pair of conductors connected with an anode ofthe igniter, the other of said pair of conductors connected with acathode of the igniter, each of said pair of conductors being insulatedso as to be electrically isolated from all other portions of saidigniter; forming an electrical connector having a pair of conductors anda body portion, the body portion operably coupleable to the gun, each ofthe pair of conductors adapted to engage and connect with a separate oneof the pair of conductors of the igniter when the electrical connectoris engaged with the igniter, each of the pair of conductors beinginsulated so as to be electrically isolated from all other portions ofthe electrical connector and the gun; connecting each of the pair ofconductors of the electrical connector with a separate conductor of thepower cable; connecting the electrical connector with the electricalconnector portion of the igniter; and forcing the electrical connectorand the igniter together with a first biasing force, the first biasingforce being of sufficient magnitude to prevent arcing between theconductors of the igniter and the conductors of the electricalconnector.
 17. A combination high-energy electrical connector andelectro-thermal chemical igniter assembly comprising: an electro-thermalchemical igniter including a base portion adapted to be operably coupledwith an ammunition cartridge case, and an electrical connector portionin said base portion, the electrical connector portion including anniter supply conductor and an igniter return conductor, the ignitersupply conductor having a supply socket and the igniter return conductorhaving a return socket, the igniter further including means forelectrically isolating said igniter supply conductor and said igniterreturn conductor from said base portion; and a connector including abody portion adapted to be operably coupled with a gun breech, aconnector supply conductor having a distal portion adapted to engage andelectrically connect with said supply socket to define a current supplypath, a connector return conductor adapted to engage and electricallyconnect with said return socket to define a current return path, andprojecting means for electrically isolating said current supply path andsaid current return path from said body portion.
 18. The assembly ofclaim 17, wherein the electrical connector portion of the ignitercomprises a center igniter supply conductor and an annular outer igniterreturn conductor surrounding the center igniter supply conductor and theconnector comprises a center connector supply conductor having a distalsupply portion adapted to engage and electrically connect with thesupply socket of the center igniter supply conductor, and an annularouter connector return conductor surrounding the center connector supplyconductor and having a distal return portion adapted to engage andelectrically connect with the outer igniter return conductor.
 19. Theassembly of claim 17, wherein the connector supply conductor islongitudinally slidable, and wherein the connector further includes apre-load spring arranged so as to resist proximal sliding of the supplyconductor when the igniter is connected with the connector.
 20. Theassembly of claim 17, further comprising means for biasing the connectorand the igniter together with a force sufficient to prevent arcingbetween the conductors of the connector and the conductors of theigniter.
 21. The assembly of claim 17, wherein the means forelectrically isolating the igniter supply conductor and the igniterreturn conductor from the base portion comprises a plurality ofinsulators.
 22. The assembly of claim 11, wherein the means forelectrically isolating the connector supply conductor and the connectorreturn conductor from the body portion comprises a plurality ofinsulators.
 23. An electro-thermal chemical gun system comprising: anammunition round having an electro-thermal chemical igniter; a gunadapted to receive and fire the ammunition round; a high-energy powersource; a cable connected to the high-energy power source; and aconnector for connecting the cable to the igniter, the igniter,connector, and cable being adapted to provide a current supply path anda current return path, the current supply path and current return pathbeing electrically isolated from the gun.
 24. The system of claim 23,wherein the igniter includes a base portion operably coupled to theammunition round, and an electrical connector portion in the baseportion, the electrical connector portion including a supply conductor,a return conductor, and a plurality of insulators arranged so as toelectrically isolate the supply and return conductors from the baseportion and all other portions of the ammunition round.
 25. The systemof claim 24, wherein the connector includes a body portion operablycoupled with the gun breech, a supply conductor electrically connectablewith the supply conductor of the igniter, a return conductorelectrically connectable with the return conductor of the igniter, and aplurality of insulators arranged so as to electrically isolate thesupply and return conductors from the body portion and all otherportions of the gun.
 26. An electro-thermal chemical igniter for anammunition round comprising: an anode portion; a cathode portion; aplasma containment portion having a plasma channel formed therein, theplasma channel having a pair of opposing ends; a pair of primaryelectrodes, one of said primary electrodes electrically connected withsaid anode portion and disposed at one end of said plasma channel, theother of said primary electrodes electrically connected with saidcathode portion and disposed at the other end of said plasma channel; awire disposed in said plasma channel, said wire electrically connectingsaid primary electrodes; and a plurality of secondary electrodes spacedapart on said wire, said secondary electrodes being positioned so thatthe shortest distance between any of said plurality of secondaryelectrodes and any immediately adjacent primary or secondary electrodeon said wire is less than the shortest distance between said pair ofprimary electrodes.
 27. The igniter of claim 26, further comprising abase portion adapted to be operably coupled with an ammunition cartridgecase, and an electrical connector portion in the base portion, theelectrical connector portion including a supply conductor connected withsaid anode, a return conductor connected with said cathode, and aninsulator portion arranged so as to electrically isolate the supply andreturn conductors from the base portion.
 28. An electro-thermal chemicaligniter for an ammunition round, said ammunition round including acartridge case presenting a longitudinal axis, the igniter comprising:an anode portion; a cathode portion; a base portion adapted to beoperably coupled with the cartridge case; and an elongate plasma rodportion operably coupled with said base portion and adapted to bepositionable along the longitudinal axis of the cartridge case, saidplasma rod portion having a pair of opposing ends, said anode portionpositioned proximate one of said pair of ends, said cathode portionpositioned proximate the other of said pair of opposing ends, saidplasma rod portion enclosing a plasma generation region extendingbetween said anode portion and said cathode portion, said plasma rodportion further having a plurality of generally radially directed ventapertures formed therein, said vent apertures extending between saidplasma generation region and the exterior of said plasma rod portion.29. The igniter of claim 28, further comprising an electrical connectorportion in the base portion, the electrical connector portion includinga supply conductor connected with said anode portion, a return conductorconnected with said cathode portion, and an insulator portion arrangedso as to electrically isolate the supply and return conductors from thebase portion.